I'm embargoed from telling you anything about Looper, despite the fact that I snuck into a test screening of it last year (read my thoughts from that screening here). But I will tell you this: the clip above is a heavily edited version of the diner scene where Joseph Gordon-Levitt confronts his older self, played by Bruce Willis. If you're worried about spoilers you should be okay, as the clip excises a lot of stuff that is about the plot and rather focuses on two things: how the movie handles time travel and the great performances of the two leads.
In the film Joseph Gordon-Levitt is a Looper. These are guys whose job is killing and disposing of people sent back from the future. When the future contract is closed, they send your own self back to kill and then pay you off, giving you knowledge that you have 30 years to live. Bruce Willis is JGL's future self, but the killing gets botched. Now a future man is running around, JGL's criminal employers want both versions of him dead and Willis has some plans of his own.
This is a great movie. It opens September 28th. Expect more Looper stuff on BAD in the coming weeks.